The Art of SQL

I got a lot out of the first half or so of this book. It did a great job helping me build a better mental model of how a database and query engine works internally, and what tradeoffs various techniques and design choices might be making. I wound up skimming some of the latter sections on data warehousing and relational tree building/querying techniques.

"The Art of SQL" was eye-opening. This book is for people who know SQL syntax but don't yet have a deep understanding of the implications of relational theory on how a functionally correct query can nonetheless be completely wrong (and have performance, scalability, and contention consequences). It has changed the way I think about structuring my queries and has helped me to write much better SQL than I did before.